In order to increase the rate at which a computer system can execute instructions, computer manufacturers have adopted various multiprocessor architectures. First used in mainframe and high-end minicomputers, multiprocessor architectures are now commonly available in lower-end computer systems. Manufacturers commonly sell multiprocessor computer systems with fewer processors than the maximum number of processors that can be included in the system. The purchaser of such a system can later expand the multiprocessor computer system to increase its performance by purchasing additional processors and adding those additional processors to the system.
There are many different types of processors, or CPUs, manufactured for use in computer systems. Generally, a given manufacturer will produce different types of CPUs that each have a unique model number. For example, the Intel microprocessors included in personal computer (“PC”) systems include the 8086, 80286, 80386, 80386SX, 80486DX, Pentium, and Pentium II processors. Within a given model number of processor, a manufacturer generally produces many different revisions. A new revision may include fixes to problems recognized in older revisions, and may include enhancements to the functionality and performance of the processor.
Additional processors added to a multiprocessor PC system must, in general, be compatible with the processors already included in the system, both in model number and revision number. Processor manufacturers produce lists or tables that include processor compatibility information. Thus, the owner of a multiprocessor PC system that wishes to expand the system by adding an additional CPU must first determine the model and revision numbers of the CPUs currently residing in the PC system and then use the compatibility information provided by the processor manufacturer to select an additional CPU for purchase that is compatible with the CPUs already residing in the system.
The model and revision numbers of a CPU are generally printed or stamped onto the surface of the CPU. However, modern high-speed CPUs are generally enclosed within heat sinks that obscure the model and revision number information. The heat-sink-enclosed CPU is often additionally obscured by a cooling fan mounted on top of the heat sink. The owner of a PC typically determines the model and revision numbers of the CPUs within the computer system by removing the cooling fan and heat sink. This disassembly process is time-consuming and can subject the CPU and circuit board that contains it both to mechanical damage and to electrical damage due to static discharges.